A system in which a wireless network is built in a house and apparatuses such as a personal computer (PC), a smartphone, a television receiver, and an audio reproduction system can be connected over a wireless network has been recently implemented. There is a “multi-path problem” as a problem in such wireless transmission. In a multi-path environment, a reflected wave is present with respect to a direct arriving wave. Therefore, a phenomenon that a reception level is greatly lowered occurs in such a manner that the phases of the direct arriving wave and the reflected wave are inverted and those waves are received by an antenna, in a manner that depends on a reception position. In a case where a reception terminal is small, the terminal can be set at a best reception position by changing the orientation of the terminal. However, in a case of a large apparatus such as a television receiver and an audio reproduction system, it is difficult to easily change the orientation and further, it is impossible to change the orientation also in view of circumstances associated with a viewing position and a listening position.
A “diversity antenna”, a “sector antenna”, and the like exist as conventional techniques for such a problem and are generally well known. Those are techniques of arranging a plurality of antennas apart from one another to lower the correlation and selecting an antenna having a highest reception level from among them. In this technique, the plurality of antennas is provided as options for each reception position. Therefore, the multi-path problem is alleviated. However, in those conventional techniques, firstly, a plurality of antennas is necessary and secondly, arrangement of the antennas apart from one another to provide a lower correlation is necessary, and thus there is a problem in that a space required for mounting the antennas becomes larger.
Patent Literature 1 has described a configuration in which a switch 3 performs switching between an antenna apparatus, which is formed by radially arranging film-like coil elements on a printed board, and a transceiver. Each of elements C1 to C8 in the radial form, which are described in Patent Literature 1, is an antenna and varies the directivity by combining outputs of the plurality of antennas each having different angles. The switch 3 is adapted to switch only an output RF signal of the antenna (module element)